"The first business of government is to keep people safe and the prevalence of guns makes people less safe," Mitchell told The Standard-Times Thursday.

The issue of gun violence trickles down through the community and hinders economic development, makes schools less successful and diminishes people's quality of life, he said.

"It's an enormous issue that cuts across every aspect of life in the city," said Mitchell, a former federal prosecutor.

He was one of a handful of mayors who spoke in Boston at a meeting Thursday of the Mayors Against Illegal Guns, a coalition of 800 mayors nationally. The federal legislation proposed by the group has four parts:

A requirement that every gun buyer pass a criminal background check. A ban on military-style assault weapons and high-capacity guns similar to the prohibition in Massachusetts. The establishment of gun trafficking as a federal crime. Stronger penalties for the so-called "straw purchasing" of guns where people who can't pass a background check either ask or pay someone to buy a gun for them.

The mayors' coalition sent an open letter to the president and Congress calling for immediate action to reduce gun violence in the wake of the tragedy in Newtown, Conn.

"We believe that with this latest national tragedy and the high incidence of gun violence that continues to plague our streets, we have reached a tipping point. The nation's mayors pledge to work with you to build a safer America for our children and all of our citizens," the letter said.

Mitchell said in New Bedford last year there was only one homicide by gunshot, which he called "a tribute" to police and county prosecutors, civilian witnesses and federal agencies.

"In order to sustain that we need help at the federal level," he said.

Police Chief David A. Provencher agrees with the mayors' recommendations. "I think all of those proposals make sound sense and will provide us with a safe community," he said.

Illegal guns have long been the major cause of gun violence in New Bedford, according to the chief. "It's a staple of the violence we have seen," he said.

Rep. William Keating, D-Mass., a former Norfolk County district attorney, said he is in complete agreement with the mayors. The assault weapons, which are being targeted by the mayors, fire off multiple rounds in seconds and kill at will, he said.

"We have seen it in Aurora. We have seen it in Newtown. We have seen it in Arizona," he said.

"These are good, common-sense approaches that will save lives and prevent people from having guns who shouldn't have them because of their backgrounds," he said.

Rep. Antonio F.D. Cabral, D-New Bedford, said he supports the proposals and has filed legislation to close a loophole in the state's assault weapons ban.

"We need to keep guns out of the hands of those who shouldn't have them," he said.

Assault rifles like the AR-15, which was used in the December 2006 attack at the former Foxy Lady n New Bedford that killed a bouncer and the club's general manager, can be legally bought and owned if they were manufactured prior to 1993, he said.

He said he also wants to see Massachusetts follow New York's example and reduce the number of rounds in the magazines from 10 to seven.